Abstract: Iron oxide as a support surface imprinting,by two- stage polymerization,surface modification on its functional monomer( MAA),and the template molecule( TBT),a crosslinking agent( EGDMA) and porogen( acetonitrile) polymerization. Research specifically recognize TBT magnetic molecularly imprinted polymer prepared successfully(Fe_3O_4@ MIPs).Its physical was be characterization,and its adsorption capacity was be selection.The results showed that the Magnetic molecularly imprinted polymer compared to traditional imprinted polymers had a greater adsorption capacity,significantly more selective adsorption,magnetic separation and because of its characteristics,the pre-treatment process became easier and faster.Magnetic molecularly imprinted polymer as an adsorbent enrichment and separation,in a variety of seafood sample detection limit of 1.0 ng / g,and the recovery was 79.74% ～ 95.72%,the linear range of 5 ng / g to 1000 ng / g. Mussels,cockles and large yellow croaker were mud and HPLC- ICP- MS analysis,sample recoveries in the range of 79.74% ～ 95.72%,RSD 1.3% ～4.7%. The method of total analysis time was shorter,lower detection limit,wider linear range,could be better applied to the determination of seawater and seafood tributyltin.